6 Neurodynamics and Peripheral Nerve Entrapment

Question 1

What’s the motor distribution of the Sciatic nerve?

Answer 1

knee flexion

Question 2

What’s the motor distribution of the femoral nerve?

Answer 2

hip flexion, knee extension

Question 3

What’s the motor distribution of the tibial nerve?

Answer 3

ankle, toe plantar flexion

Question 4

What’s the motor distribution of the common peroneal nerve?

Answer 4

ankle, toe dorsiflexion, ankle eversion

Question 5

What’s the L1 myotome?

Answer 5

nothing

Question 6

What’s the L2 myotome?

Answer 6

hip flexion

Question 7

What’s the L3 myotome?

Answer 7

knee extension (patella DTR)

Question 8

What’s the L4 myotome?

Answer 8

ankle dorsiflexion

Question 9

What’s the L5 myotome?

Answer 9

1st toe extension

Question 10

What’s the S1 myotome?

Answer 10

ankle eversion, p.f., hip extension (achilles DTR)

Question 11

What’s the S2 myotome?

Answer 11

knee flexion

Question 12

Are diminished reflexes a nerve root or peripheral nerve issue?

Answer 12

exclusively a nerve root issue

Question 13

What’s piriformis syndrome?

Answer 13

compression or irritation of the sciatic nerve by the piriformis muscle or exit point from the pelvis

Question 14

What are some causes/contributing factors to piriformis syndrome?

Answer 14

• congenital: abnormalities in the course of the nerve
• muscular anomalies: structural (indirect), hypertrophy, spasms, tightness, trigger points
• fibrosis: repetitive stress, direct trauma, direct compression (prolonged sitting)
• vigorous physical activity
• postural and/or gait abnormalities: leg length discrepancy, hyperlordosis
• joint dysfunction
• pregnancy

Question 15

What are common presentations for piriformis syndrome?

Answer 15

• unilateral pain and/or tingling/numbness in the hip, back of thigh, calf and foot in distribution pattern of sciatic nerve
• difficulty (pain/discomfort) when sitting for prolonged periods, standing from seated position, walking up stairs
• joint: reduced hip ROM, SIJ dysfunction – may be due to altered posture and/or gait (antalgic gait), or shortening of the piriformis muscle

Question 16

What are rule ins for piriformis syndrome?

Answer 16

• DDD of lumbar spine, lubosacral radiculopathy, lumbar facet irritation, spondys
• ischial tuberosity/trochanteric bursitis
• myofascial pain syndrome (glube min TrP - peudosciatica)
• referral pain: piriformis, gluteus maximus/med/min, QL

Question 17

What’s radiculopathy?

Answer 17

compression of spinal nerve root

Question 18

What’s myelopathy?

Answer 18

compression of the spinal cord (classified as spinal cord injury if MOI is trauma; myelitis if underlying cause is inflammation)

Question 19

How is the straight leg raise (supine; nerve tension test) conducted?

Answer 19

1. medial hip rotation, then flexion with knee extended
2. ankle dorsiflexion (tibial nerve)
3. ankle plantar flexion and foot inversion (common peroneal nerve)
4. hip adduction (sciatic nerve)
5. increasing hip medial rotation (sciatic nerve)
6. passive neck flexion (SC, meninges and sciatic nerve)

Question 20

What are modifications for the SLR test (supine) (i.e. to test specific nerves)?

Answer 20

Question 21

How is the Femoral Nerve tension test conducted?

Answer 21

side lying on unaffected side

1. unaffected side: grasping knee in full hip flexion
2. affected side: passive hip extension with full knee flexion
3. thoracic and cervical spine flexed
4. cervical extension is the desensitizing test

Question 22

How is the slump test conducted?

Answer 22

(tests entire nervous system)

1. hands behind back
2. thoracic flexion
3. extend one knee
4. dorsiflex foot of extended knee
5. cervical flexion
6. extend other leg with cervical flexion